Among the various types of inorganic nanoparticles, superparamagnetic iron oxide nanoparticles have been identified as the most promising for use in biomedicine. They are usually prepared in the form of aqueous dispersions, which are not physically stable, representing an important technological challenge. In order to improve the chemical, microbiological and above all physical stability of nanoparticles, researchers have recently been paying a lot of attention to the development of methods for drying nanoparticle dispersions. The aim of this master’s thesis was to use electrospinning as an alternative method for drying superparamagnetic nanoparticle dispersions. With the aim of producing a dry product, which will be rapidly and easily dispersed in purified water and in which the nanoparticles will retain their initial properties, water-soluble polymers polyethylene oxide and poloxamer 188 in a 1:1 mass ratio were added to the initial dispersion of superparamagnetic nanoparticles before electrospinning. By systematically increasing the proportion of superparamagnetic nanoparticles in the dispersion, we determined the maximal content of superparamagnetic nanoparticles in the electrospun product, which can still be successfully redispersed. The efficiency of the reconstitution of superparamagnetic nanoparticles from the electrospun product was studied by evaluation of their hydrodynamic particle size, size distribution and zeta potential, while the morphology of the electrospun products was evaluated by scanning electron microscopy and the content of superparamagnetic nanoparticles and moisture in the electrospun products by thermogravimetric analysis. Based on the results, we have determined that the maximal content of superparamagnetic nanoparticles in the electrospun product, which can still be rapidly and easily reconstituted, while initial properties of superparamagnetic nanoparticles are preserved, is 65% (w/w). Furthermore, we investigated the influence of the polymer concentration in the electrospinning dispersion on the properties of the electrospun product. The results show that the polymer concentrations in the electrospinning dispersion significantly affects both, the morphology of the electrospun product and the efficiency of the reconstitution of superparamagnetic nanoparticles from the obtained electrospun product. Among the studied polymer dispersions for electrospinning (24, 42 and 64 mg/mL), the dispersion with concentration of 42 mg/mL enabled the production of nanofibers (with beads), from which superparamagnetic nanoparticles were most efficiently reconstituted.
|
